found one I think I can get for 250. is that a good deal?. ( looking for an average skim board to keep in the boat?) I figure this would be good for guests who want to try skim ( I am mainly surf style)

Good deal will depend on condition mostly and to a lesser extent year. I can say I have fixed an awful lot of them.
The first few years were polyurethane boards. Later they switched to polystyrene/epoxy and full paint cover (candy coat).